[20180625]简单计算日志生成率.txt

[20180625]简单计算日志生成率.txt

--//执行前最好做一次日志归档.主要目的了解正常业务时redo的生成率.
--//alter syste archive log current;

SELECT thread#
        ,sequence#
        ,first_time
        ,next_time
        ,blocks * block_size / 1024 / 1024 MB
        , (next_time - first_time) * 86400 sec
        ,  blocks
         * block_size
         / 1024
         / ( (next_time - first_time) * 86400)
            "KB/s"
    FROM v$archived_log
   WHERE     ( (next_time - first_time) * 86400 >= 1)
         AND first_time BETWEEN TRUNC (SYSDATE) - 1 AND  TRUNC (SYSDATE) + 1
         AND dest_id = 1
ORDER BY first_time;

--//注:((next_time-first_time)*86400 >=1), 取消一些快速切换的情况,避免存在大的误差.
--//可以根据需要调整.